In electric motors, in particular in external rotor motors, sufficient cooling on the stator bushing and the electronic unit is essential for power and a useful life. An improvement in cooling is always desirable. In the prior art, for example, DE 10 2012 107 109 A1, it is provided, for this purpose, to guide a cooling air stream specifically along components to be cooled. In practice, this works very well. However, the maximum possible cooling capacity has not yet been fully exploited. On the contrary, in addition to the guiding of the cooling air stream, adaptations of the rotor generating the cooling air stream and consequently of the air stream itself are possible. In addition, this also enables a reduction of the noise generation.
The underlying aim of the disclosure therefore is to increase the cooling capacity generated by an air-conveying wheel in an electric motor. Furthermore, the aim of the disclosure is to reduce noise generated by the air-conveying wheel.